System for wireless transmission of writing, pictures, and the like



P". H. PETERSEN.

TRANSMISSION'OF WRITING, PICTURES, AND THE LIKE. APPLICATION men'ocr.21. 192i.

SYSTEM FOR WTRELESS Patented NOV- 28, 1922.

2 SHEETS-SHEET I.

Ti; g; w

M. H. PETERSEN.

SYSTEM FOR WIRELESS TRANSMISSION OF WRITING, PICTURES, AND THE LIKE.

APPLICATION FILED OCT. 21. I921.

1,436,676. Pate'ntd Nov. 28,1922. I

2 SHEETS-SHEET 2- SATES PAINT OFFlCE.

MAGNE HERMOD PETERSEN, F CHRISTIANIA, NORWAY.

SYSTEM FOR WIRELESS TRANSMISSION OF WRITING, PICTURES, AND THE LIKE.

Application filed. October 21, 1921. Serial No. 509,416.

To all whom it ma concern:

Be it known that MAGNE HERMOD PETER- SEN, a subject of the King ofNorway, residing at Sorgenfrigate 36, Christiana, Norway, have inventedcertain new and useful Improvements in Systems for Wireless Transmissionof Writing, Pictures, and the like (for which I have made applicationfor pattents in Norway, September 9, 1920, Ser. No. 21,733; Holland,July 26, 1921, S. No. 19,970; Sweden, September 5,1921, S. No. 3,158;Denmark, September 3, 1921, S. No. 2,113; France, August 24;, 1921, S.No. 148,4:85; Germany,-Nov. 1, 1920, 'S. No. P. 40,887 England, Aug. 22,1921, S. No. 22,273; Italy, Sept. 1,1921,N0. 300 3030; Poland, July 26,1921, S. No. 9,089; and Spain September 1. 1921, S. No. 4420) and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to makeand use the same, reference being had to theaccompanying drawings, and to letters or figures of reference markedthereon, which form a part of this specification.

The present invention relates to the sys terns for transmission ofwriting, pictures and the like, in which part of the current circuit ofan alternating current generator connected to the transmission leads isshortcircuited by means of a contact arrangement, which is so actuatedby means of the writing at the sending station, that the shortcircuiting is started or interrupted by means of a contact needlepassing over the written lines.

The present invention relates to the adaption of this system to wirelesstransmission of writing, and has for its object a method by means ofwhich the known systems for transmission of the pictures or the writingcan be used practically without modifica-' tions for this purpose.

On the drawing is diagrammatically illustrated a form of the invention.

Fig. 1 illustrates a diagram for a sending station and Fig. 2 thediagram for a receiving station.

' oscillations is regulated, and by means of the secondary winding ofthe high frequency transformer, energy is received from the sendingapparatuses.

The sending apparatuses comprise a vacuum tube generator 4 of knownconstruction and effect. This vacuum tube generator generates continuous(undamped) oscillations, the wave length of which is adapted for thepurpose, for instance 600 m. The wave length is regulated by means ofthe oscillating'circuit 56, and the oscillations are transformed fromthe primary winding 6 of the high frequency transformer to the secondarywinding 3 and emanate from the antenna in the form of electromagneticwaves. 7 is the sending cylinder of the copy telegraph apparatus. Thetelegram, comprising a picture or writing of any kind is transferredchemigraphically to the cylinder in such a manner that the lines areelectrically insulating. During the rotation of the cylinder a contactneedle describes a helical line on the same. When the contact needletouches the metal, a contact is formed, and this contact is broken, whenthe needle is passing over a line of the writing or picture. From thecontact needle and metal of the sending cylinder, two lines lead to thescreen circuit of the vacuum tube generator, and are connected at points8, 9 in parallel to the screen coil 10. It will be understood that whenthe-contact needle on the cylinder is in contact with the same, coil 10is short circuited, whereby the emanation of waves from the antenna isintercepted, and when the contact needle passes an insulating part ofwriting, the short circuiting is interrupted, and continuous (undamped)waves emanate from the antenna as in a modern radio station providedwith vacuum tube sender. The waves emanated are taken up at thereceiving station by the antenna 11 and conducted over the antenna coil12 to the antenna coil 13 of the receiving transformer, whereupon it istransferred inductively to high frequency intensifying detector and lowfrequency intensifier of a known type and placed together in apparatus14. The sa1d high frequency circuits can however not be used directlyfor driving the receiving a paratuses of the copying telegraph. T ereceiving apparatuses, which can be used,

comprise oscillograph receivers, spark receivers and others. In thepresent case it 1s supposed, that an oselllograph receiver is used, andthis apparatus is adapted to work with alternating currents, thefrequency of which may vary from a couple of hundred to 12,000 cyclesper second. If the incoming waves have a frequency of 500,000 cycles persecond, corresponding to 900 m. waves. the frequency must for instancebe reduced to 1,000 cycles'per second. This is done in a known manner bygenerating at the receiving station oscillations with a somewhat higher,or lower frequency than the incoming waves. The said oscillations arecaused to interfere with the incoming, thus producing the well knownbeat effect, i. e. the resultant oscillation besides their individualhigh frequency, and this beat frequency is exactly equal to thedifference between the frequencies of the interfering oscillations. Onthe diagram is illustrated beat effect for the frequencies 190,000 and'190,100 cycles per second. The beat fre quency in that case will be 100beats per second. If the incoming oscillations have a frequency of500,000 cycles per second, and the interfering oscillations have afrequency of 501,000 or 499,000 cycles per second the beat frequencywill be 1,000 per second. The interfering oscillations are generated inthe vacuum tube generator 15 and are transmitted by means of a couplingcoil 16 to coil 17, where they interfere with the incoming oscillations.As the resultant oscillations with beat frequency 1,000 'pass thedetector, they are rectified in the usual manner, and finally, aftersufficient low frequency intensifying reach the low frequencytransformer 18, to which the loop 19 of the oscillograph receiver isconnected. The said oscillograph serves to register theelementary signson the rotating cylinder 20 in the same manner as in a copying telegraphfor line-telegraphy. In this manner the transmission of signs takesplace.

The present method, however, is also adapted for solving the wirelesssynchronizing problem, which is also indicated on the drawing.

It is well known that it is absolutely nec essary to have an idealsynchronism, when thecopy telegraph is to be used for continuousoperation. According to the present system for wireless transmission,the sending and receiving apparatus are driven by means of single phasesynchronous motors. If these motors shall operate in synchronism, theymust be driven from the same source of power, so that all variations inthe current take place simultaneously and in the same manner in bothmotors. Synchronous motors operate with comparatively low frequency forinstance 50 to 100 periods per second. The power for driving thesesynchronous motors must therefore in the first instance be transferredas electromagnetic Waves, and secondly must be given a frequencysuitable for driving synchronous motors. This, according to the presentinvention is obtained in the following manner:

At the sending station there is used two vacuum tube generators. Thesework with a frequency adapted for the radio devices customarily used. Ifthe signs are'to be sent for instance with a wave length of 600m.,- awave length of for inst. 1600111. will be suitable for driving thesynchronous motors. If the said motors are to work with a frequency of100 cycles per second, this may be effected by making one vacuum tubegenerator 21 produce in the circuit 22 oscillations of frequency 190,000cycles per second, while'the second Vacuum tube generator 23 produces incircuit 24 oscillations with frequency 190,000 or 189,000 cycles persecond. Both kinds of oscillations are transmitted to the antennathrough the respective high frequency transformers 28-29, and'in theantenna the oscillations interfere and produce an oscillating energy ofsufficient strength to reach the receiving station and with a beatfrequency of 100. The antenna circuits 1,27, 28, 29, 30 and 31 are tunedfor a medium frequency, in the present case either 190,050 or 189,950cycles per second. This energy is adapted for long distance transmissionand at the same time can be utilized for driving synchronous motors. Atthe sending station part of the energy is transferred through coil 32 tothe vacuum tube rectifier 33, and the beat frequency is transferredthrough the low frequency transformer 341 to the secondary of thetransformer, to which the synchronous motor 35 is connected. Thesynchronous motor accordingly receives alternating currents of 100periods, and by means of the connecting between coils 30 and 32, thestrength of the energy is so regulated, that'it is suitable for thesynchronous motor. The antenna continuously emanates the interferingoscillations from vacuum tube generators 21 and 23. At the receivingstation the interfering waves are received in the antenna circuits 11,36, 37 and 38, which is tuned to a medium value as above specified. Asthe branches 2, 3 at the sending station and 12, 13 at the receivingstation is tuned to a shorter wave length, 600m., the long waves can notpass this way, but are forced to pass the antenna circuit tuned to thelong waves.

When the interfering oscillations pass 37 on the receiving station, theyare transferred through the high frequency transformer 37, 38 to thehigh frequency intensifierand detector 39 and the low frequencyintensifier 40, whereupon the beat frequency asses the low frequencytransformer 11 and supplies alternating current of frequency 100 to thesynchronous motor 42. It should be noted that at the receiving stationit is necessary to intensify the incoming energy sufficiently fordriving the synchronous motor. It is therefore necessary to use highfrequency as well as low frequency intensifying, which is known fromradio telegraphy.

It will be understood from the above, that the synchronous motors at thesending and receiving stations are driven from the same source of power,so that the synchronism between the said motors will be accurate.

On the drawing there is illustrated a number of different vacuum tubegenerators. This, however, it done only for the sake of clearness, asthere is nothing to prevent the combination of said vacuum tubes.in onevacuum tube of suitable energy for the distance between sender andreceiver.

I claim:

1. The method of wireless telegraphy between stations, ,which comprisesreceiving signaling oscillating current energy and combining it with theenergy of a separately produced auxiliary current whose frequency isslightly different from the frequency of the received current, andtranslating the combined energy for telegraphic signals andsimultaneously producing at one station oscillating current energies ofdifferent frequencies differing from the frequency of the aforesaidreceive-d oscillations and combining, andtranslating the latter combinedenergies at both stations. J

2. The method of wireless telegraphy between stations, which comprisesreceiving oscillating current wave energy and combining therewith at thereceiving station auxiliary alternating current to produce beatstherewith, and producing at one of the stations correlated currentenergies differing in frequency materially from the receivedoscillatlons, and combining said latter energies at both stations, andtranslating the combined energies, at both stations into synchronizedmechanical movement.

3. The method of wireless telegraphy between stations, which comprisesreceiving oscillating current wave energy and producing a beat frequencyof one value by which intelligence is received and simultaneouslyproducing at one of the stations combinable oscillations differingmaterially in frequency from the aforesaid received oscillations toproduce a beat frequency at both stations of a different Value from thebeat frequency for intelligence, and translating the latter combinedenergies into mechanical energy at both stations.

4. The method of wireless telegraphy be- .twcen stations, whichcomprlses sending oscillating current wave energy from one station toanother, combining with said energy at the receiving station alternatingcurrent energy to produce beats, translating the combined energies intomechanical movement in accordance with variations in the oscillatingcurrent wave'energy correspondtween stations, which comprises receivingsignaling oscillating current energy and combining with it at thereceiving station energy of a separately produced auxiliary currentwhose frequency differs but slightly from the received energy to producebeat effect, and translating the combined energies for telegraphicsignals; simultaneously translating at both stations combinedoscillating energies having a beat effect differing materially infrequency from the aforesaid beat effect, and translating the combinedenergies into synchronous mechanical movement at the stations.

6. The method of wireless telegraphy between stations, which comprisesreceiving signaling oscillating current'energy, combining therewith anauxiliary current to produce a'beat effect, and translating the combinedcurrent for telegraphic signals, simultaneously generating at a stationoscillating current energy materially differing in frequency from theaforesaid energy and combining with the latter energy a secondoscillating current differing in frequency from the frequency of thelatter energy and translating the combined energies at both stationsinto synchronized mechanical movement. v

7. The method of wireless telegraphy between stations which comprisestransmitting signaling oscillating cu'rrent energy. from one station toanother, combining therewith at the receiving station a current toproduce a beat effect and translating the com- .bined energies fortelegraphic signals; si-

multaneously maintaining between the stations combined oscillatingcurrents whose beat frequency materially differs from the frequency ofthe signaling current, and translating the latter combined current intosynchronized mechanical movement at the stations.

8. In wireless telegraph apparatus, means for receiving undampedoscillatory current of one frequency, means to produce alternatingcurrent of a frequency differing but slightly from the aforesaidfrequency to produce a beat frequency, means to reduce the beatfrequency, an osclllograph operated by the energy thus transformed,means to receive high frequency oscillations differing from the saidoscillatory current the combined energy of which produces a beat cf feetdiffering from'the aforesaid beat frequency, and means to translate saidenergy into useful current, a synchronous motor operated by such energy,and means operated by said motor to receive actinic reflections fromsaid oscillograph.

9. In Wireless telegraph apparatus, means at one station for sending awireless signaling current, means at a receiving station for combiningwith said current an alternating current of different frequency andmeans at said receiving station for translating said current forsignals;in combination with means at one station to simultaneouslyproduce a heterodyne power current at both stations difierenigmaterially in frequency from the heterodyne signal current, and meansfor translating the heterodyne power current into synchronizedmechanical movement.

10. In Wireless telegraph apparatus, means heterodyne power currentmaterially differing in frequency-from the signal current, and means atboth stations to translate said power current into synchronizedmechanical movement.

In testimonythat I claim the foregoing as my invention, I have signed myname in presence of two subscribing witnesses.

MAGNE HERMOD PE ERSEN;

Witnesses:

MORGAN BUGGE, MARGIL A. AANEESSEN.

